Temporal variation of the forest experience index in typical ecosystems of Beijing, China.

Exploring the relationship between ecosystem functions and humans is of great significance for promoting human health and well-being. Systematic quantitative indicators for the public's green experience in different ecosystems are in shortage. The quantitative indicators for the differences in green experience perception among people in different ecosystems are unavailable, which limit scientific decision-making for green recreation. Based on Technical Specification and Assessment on Forest Experience Index (DB11/T 2029-2022), combined with in-situ real-time continuous monitoring data from 10 ecological monitoring stations in Beijing, we analyzed the changes in forest experience index (FEI) of forest, wetland, and urban green space ecosystems at daily, monthly, and seasonal scales from three dimensions: comfort, health, and regulation. We further explored the similarities and differences in FEI at different time scales among different ecosystem types. The results showed that wetland ecosystem maintained the highest FEI value, followed by forest and urban green space ecosystems. At the daily scale, the FEI peaked at 7:00-9:00 and 16:00-19:00 in the study area. From spring to winter, the morning peak showed progressive delay from 7:00 in spring to 9:00 in winter, while the afternoon peak showed gradual advancement from 18:00-19:00 in spring and summer to 16:00-17:00 in autumn and winter. At the month scale, wetland had the highest mean FEI value from March to October. All the three ecosystem types showed less difference in other months. The comfort and regulatory degree increased from March to September and decreased from October to February. The maximum monthly mean values for comfort, health, and regulatory degree were in September, July, and July, respectively, while their minima were in December, March and December, respectively. Excluding meteorological warnings, the seasonal mean FEI value was highest in summer, followed by autumn and spring, and lowest in winter. Comfort, health, and regulatory degree were generally higher in summer and autumn than in spring and winter. The variation patterns of the FEI at different temporal scales had strong linkages with the regulation function of ecosystems. Our results could inform scientific recommendations for public recreation, as well as provide basic data for the enhancement of Beijing's Garden City construction and the assessment of ecosystem services.